Armrest mounting structure in automotive seat

ABSTRACT

An armrest mounting structure in an automotive seat, in which an armrest is provided between a fore-and-aft movable seat cushion frame and a seat back frame which is variable over its inclination angle responsive to the fore-and-aft movement of the seat cushion frame, with such an arrangement that a reinforcing bracket is provided, extending over the seat back and seat cushion frames, and the armrest is partly supported by such reinforcing bracket, so as to increase the strength of the seat back frame for supporting the armrest.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a structure for mounting an armrest inan automotive seat, and is in particular directed to the armrestmounting structure in the seat of type having a fore-and-aft movableseat cushion frame and a seat back frame connected pivotally with theseat cushion frame, with the arrangement that fore-and-aft movement ofseat back frame causes angular variation of seat cushion frame relativethereto, and wherein the armrest is pivotally connected to the lowerframe section of seat back frame such as to be rotatable between a useposition projecting forwardly of the seat and a non-use position restingon the seat back.

2. Description of Prior Art

FIGS. 1 and 2 illustrate an example of conventional armrest mountingstructure wherein a seat cushion frame (CF) is of a type movableforwardly and backwardly, forming a seat cushion (SC), and a seat backframe (BF), which forms a seat back (SB), is pivotally connected withthe seat cushion frame (CF) such as to be rotatable forwardly andbackwardly relative thereto, for allowing inclination angle adjustmentof the seat back frame (BF), wherein an an armrest (A) is pivotallyconnected on the lower side of lower frame section (BF1) of seat backframe (BF). According to this structure, for example, when the seatcushion (SC) is moved forwardly, the upper part of seat back (SB) islowered along a cabin wall (F) of automobile, while being rotated aboutthe pivot point to vary its inclination angle. Designations (X)(X)denote a pair of bearing members on which the seat back frame (BF) ismounted in a manner to be slidable vertically and rotatable thereabout.

The seat back frame (BF), as viewed from FIG. 2, is formed by the lowerframe section (BF1), a right-side part (BF2) thereof, a righ-sidelateral frame section (BF4) whose lower end (BF3) is fixed to theright-side part (BF2) of lower frame section (BF1), an upper framesection (BF7), wherein the upper end (BF5) of right-side lateral framesection (BF4) is fixed to the upper frame section (BF7), and a pair ofspaced-apart intermediate frame sections (BF12)(BF13) which are extendedbetween the upper and lower frame sections (BF7)(BF1). With regard tothe two intermediate frame sections (BF12)(BF13), taking one (BF12) ofthem for example, its upper part (BF10) and lower part (BF11) are fixedto the left-side end part (BF8) of upper frame section (BF7) andleft-side end part (BF9) of lower frame section (BF1).

As seen in FIG. 2, there are a pair of spaced-part forwardly projectedarms (B1)(B2), such that the left-side arm (B1) is fixed to a point ofthe lower frame left-side end part (BF9) to which the lower end (BF11)of left-side intermediate frame section (BF12) is fixed in a mannerorthogonal relative thereto, and that the right-side arm (B2) is fixedto a point of the same part (BF9) to which the lower end (BF14) ofright-side intermediate frame section (BF13) is likewise fixedorthogonally relative thereto.

As indicated by the phantom line, armrest body (A) is at its rearwardend part pivotally supported by the two arms (B1)(B2), such that thearmrest body (A) may be moveable between a use position to projectgenerally horizontally for receiving arm of an occupant sitting on theseat and a non-use storage position to be stored in the central storagesection in the seat back (SB).

The lower frame section (BF1) is formed with a pair of spaced-apartdownwardly projected connecting arms (BF15)(BF15), such that left-sideone of the connecting arms is located between the two armrest supportarms (B1)(B2) at the left-side end area (BF9) of the lower frame section(BF1), whereas right side one of them is located at the right-side endarea (BF2) of the same (BF1).

The seat cushion frame (CF) has a pair of spaced-apart connecting arms(CF1)(CF1) such as to extend in correspondence with the respective twoconnecting arms (BF15)(BF15) associated with the seat back frame (BF).Those connecting arms (CF1)(BF15) are pivotally connected together in amutually rotatable way.

Designations (BP) and (CP) denote a seat back padding of seat back (SB)and a seat cushion padding of seat cushion (SC), respectively.

With the above-described conventional armrest mounting structure,however, it has been found as a problem that an entire weight or load ofthe armrest body (A) is directly transmitted through the arms (B1)(B2)to the left-side end area (BF9) of lower frame section (BF1) which isonly supported by the connecting arms (BF15)(CF1). As a result, in viewof the two intermediate frame sections (BF12)(BF13) of a thin wirematerial being simply welded to such left-side end area (BF9), the lowerframe section (BF1) is week in strength against the weight of thearmrest body (A), and thus such trouble has occured, that the armrestbody (A) is unstably moved or wobbled, giving an uneasy feeling to thearm of an occupant sitting on the seat.

SUMMARY OF THE INVENTION

It is a purpose of the present invention to provide an improved armrestmounting structure in an automotive seat which increases the rigidity ofa seat back frame for supporting an armrest.

To achieve such purpose, in accordance with the present invention, areinforcing bracket is provided in the seat back frame in such a manneras to extend from the lower frame member to the upper frame memberthereof. To a part of such reinforcing bracket, the armrest is pivotallyconnected. Thus, a load applied to the armrest is dispersed to both ofthe upper and lower frame members, thereby avoiding a concentration ofload to a local part of seat back frame and thus preventing deformationof same.

It is another purpose of the present invention to disperse the armrestload also to a seat cushion frame which is pivotally connected to theseat back frame.

To this end, in accordance with the present invention, the seat backframe is pivotally connected to the seat cushion frame at three points,such that three connecting arms are formed from both of the two framesand pivotally connected together. In particular, it is preferable thattwo pivotal connection points be defined where the armrest is rotatablysupported in the seat back frame. This allows the armrest load to beeffectively distributed to the seat cushion frame, and increasingrigidity at the armrest mounting area by virtue of such two pivotalconnecting points.

In one aspect of the invention, the reinforcing bracket serves as a wallto prevent invasion of a foamable base material into the armrestmounting or storage area in the seat back frame during the process forfoaming together a padding and seat back frame in a mold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an automotive seat in which aconventional armrest mounting structre is provided;

FIG. 2 is a partly broken and exploded, perspective view of a frameworkof the seat, showing the conventional structure for mounting thearmrest;

FIG. 3 is a partly broken and exploded, perspective view showing anarmrest mounting structure in accordance with the present invention;

FIG. 4 is partly broken plan view of pricipal part of the invention;

FIG. 5 is a partly broken perspective view of another embodiment of theinvention; and

FIG. 6 is a sectional view of such another embodiment as in the FIG. 5.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

At first, it should be understood that the present invention is directedto an improvement based on the previously stated prior art and sincehereinafter reference will be made to common elements of prior art, alllike designations in the prior art description above correspond to alllike ones used in the present description, without specific explanationthereon.

FIGS. 3 and 4 show a first embodiment of armrest mounting structure inaccordance with the present invention, which is distinguished over theprior art structure in terms of mounting the armrest (A) onto the seatback frame (BF).

In the present embodiment, designation (1) represents a reinforcingbracket. The reinforcing bracket (1) comprises a plate-like armrestmounting section (1a) to which the right-side lateral wall of armrestbody (A) is rotatably provided, and a plate-like securing section (1b)which is bent from the armrest mounting section (1a) at generally aright angle relative thereto.

The armrest mounting section (1a) is of a length equal to that ofarmrest body (A), and has, formed at its lower end area, a forwardlyprojected coplanar part (1c) and a pair of securing lugs (1h). In theprojected coplanar part (1c), a securing hole (1d) is formed, by way ofwhich the base part of armrest (A) is pivotally secured on the seat backframe side (BF). In the upper end part of securing section (1b), thereis defined a securing area (1e).

At a lower point designated by (1f) in the securing section (1b), thereis defined an L-shaped area (1g) extending in a direction opposite tothe armrest mounting section (1a) and terminating in the foregoing twosecuring lugs (1h).

Designation (4) denotes a generally L-shaped bracket.

As seen in FIG. 3, a securing bracket (BF16) is provided at theleft-side end area (BF8) of upper frame section (BF), such that the baseedge of the securing bracket (BF16) is welded to that upper framesection end area (BF8) and one lateral (on the left side) edge of samebracket (BF16) is welded to the left-side intermediate frame section(BF12). Further, at the left-side end area (BF9) of lower frame section(BF1), a pair of securing blocks (B1)(B2) are fixed in such a mannerthat they are spaced apart from each other a distance equal to that ofthe two intermediate frame sections (BF12)(BF13), extending across thelower frame section (BF1) in an orthogonal relation therewith, so thatthe lower ends respectively of the two intermediate frame sections(BF12)(BF13) are fixed to each upper wall of the two securing blocks(B1)(B2). As viewed from FIG. 3, the left-side securing block (B1) has asecuring surface defined at its outer lateral wall, though not clearlyshown, in which securing surface, the securing lugs (1h) of reinforcingbracket (1) is secured, while on the other hand, the right-side securingblock (B2) has a securing surface defined at its frontal wall, in whichsecuring surface, the L-shaped support bracket (4) is secured.

In FIG. 3, a pair of connecting arms (BF15a)(BF15a) are depicted to befixed at the lower frame section end area (BF9) such that each of thosearms adjoins the foregoing two securing blocks (B1)(B2), respectively.Likewise, another pair of connecting arms (CF1a)(CF1a) are depicted tobe fixed at the left-side end area of seat cushion frame (CF) in such amanner as to be pivotally connected with the two respective connectingarms (BF15a)(BF15a) of seat back frame (BF).

The reinforcing bracket (1) and L-shaped support bracket (4) arerespectively connected by pivots to the left-side and right-side lateralwalls (A1)(A2) of armrest body (A) in a free-to-rotate manner. Thesecuring of such armrest body (A) to the left-side end area of seat backframe (BF) is such that the the upper securing area (1e) of reinforcingbracket (1) is firmly secured by a bolt (2) to the securing bracket(BF16), the securing lugs (1h) of same seat back frame (BF) are firmlysecured by bolts (3) to the lateral securing surface of left-sidesecuring block (B1), and the L-shaped support bracket (4) is at its basepart (4a) firmly secured to the frontal securing surface of right-sidesecuring block (B2) by means of bolts (4c). It is therefore seen thatthe reinforcing bracket (1) extends between the upper and lower framesections (BF7)(BF1).

With the present embodiment constructed above, it is to be appreciatedthat the weight of armrest body (A) is effectively dispersed into thereinforcing bracket (1), thus being partly transmitted to the upperframe section (BF7), and into each of the two connnection points (BF15a,CF1a)(BF15a, CF1a): Namely, the armrest weight are dispersed at thosethree points and not intensively exerted on the lower frame section(BF1), and thus, the armrest (A) is supported stably at the seat backframe (BF) against wobbling. Further, the L-shaped area (1g) andsecuring lugs (1h) presents a coplanar support wall to the left-sidelateral wall (A1) of armrest body (A), thereby fully supporting thearmrest body (A) which is located at the use position projectinghorizontally from the seat back (SB), whereby the armrest body (A) atthe use position is positively supported against lateral unstablemovements. Still further, the forwardly projected armrest securing part(1a) presents an elongated wall which supports the armrest body (A)generally along its entire longitudinal length, when the armrest body(A) is located at the non-use position resting on the seat back side.Thus, at the non-use position, the armrest body (A) is also positivelysupported against lateral unstable movements.

FIGS. 5 and 6 show a second embodiment of the present invention which isdirected to an improvement of the above-stated securing bracket (BF16)and upper securing part (1e) of reinforcing bracket (1).

In this particular embodiment, in the securing bracket (BF16), anL-shaped engagement lug (5) is formed by way of punching out thecorresponding part of the bracket (BF16) such as to project forwardlythereof, and a securing nut part (6) is formed below the L-shapedengagement lug (5). On the other hand, at the upper securing area (1e)of reinforcing bracket (1), there are formed an engagement aperture (9)into which the engagement lug (5) is engaged, and a securing hole (8)which is to be aligned coaxially with the threaded hole of securing nutpart (6).

Accordingly, once the engagement lug (5) is latchingly engagement intothe engagement hole (9), it is easy to position the securing hole (8)precisely in alignment with the nut hole (6) and a securing bolt (7) canreadily be threadedly inserted through the nut hole (6), to firmlysecure the upper securing area (1e) of reinforcing bracket (1) to themating securing bracket (5).

It is noted that both paddings (BP)(CP) have in advance been foamedintegrally with the respective seat back frame (BF) and seat cushionframe (CF) in a suitable foaming mold. In this respect, the reinforcingbracket (1) serves to prevent leakage of a foamable base material intothe intermediate frame sections (BF12)(BF13) during foaming process forthe seat back padding (BP).

Finally, the present invention is not limited to the illustratedembodiment, but any other modifications, replacements and additions maystructurally be possible without departing from the scopes and spiritsof the appended claims. For instance, another reinforcing bracketsimilar to the one (1) may be provided along the right-side intermediateframe section (BF13), instead of support bracket (4). This completelyprevents invasion of foamable base material into the armrest storagearea between the two intermediate frame sections (BF12)(BF13) during theprocess for forming the seat back padding (BP) together with the seatback frame (BF) in a mold, not to mention more rigid support structurefor the armrest body (A) in the seat back (SB).

What is claimed is:
 1. An armrest mounting structure in an automotiveseat, in which said seat includes a seat cushion frame for a seatcushion which is movable forward and backward, a seat back frame for aseat back which is pivotally connected with said seat cushion frame,such as to be rotatable responsive to forward and backward movement ofsaid seat cushion frame for variation of an inclination angle relativethereto, and an armrest body is pivotally connected via a bracket meansto said seat back frame, characterized in that:said bracket meanscomprises a bracket and a reinforcing bracket; said bracket is fixedlysecured to a lower frame section of said seat back frame; saidreinforcing bracket is shaped generally in an "L" configuration, havingan upper portion fixedly secured to an upper frame section of said seatback frame, a lower portion fixedly secured to said lower frame sectionof the same seat back frame, and a forwardly projected portion extendingfrom a plane of the same seat back frame, wherein said forwardlyprojected portion is defined along a longitudinal direction of saidreinforcing bracket; and said reinforcing bracket is formed such that anupper securing part is defined at an upper end area of said reinforcingbracket, and a lower outwardly projected securing part is defined atsaid lower end area of said reinforcing bracket so as to extend in aopposite direction to the forwardly projected portion, wherein saidarmrest body is pivotally supported by said bracket and said forwardlyprojected portion of said reinforcing bracket, and wherein saidreinforcing bracket forms a side wall which acts to support a lateralwall of said armrest body when said armrest body is located in a non-useposition to be stored at said seat back frame.
 2. The armrest mountingstructure as defined in claim 1, wherein said upper and lower portionsof said reinforcing bracket are fixedly secured by means of bolts andnuts to said upper and lower frame sections of said seat back frame,respectively.
 3. The armrest mounting structure as defined in claim 1,wherein said bracket is fixedly secured by means of bolts and nuts tosaid lower frame section of said seat back frame.
 4. The armrestmounting structure as defined in claim 1 whereby, said lower framesection of said seat back frame is pivotally connected on said seatcusion frame by jointing means, and the weight of said armrest body isdispersed into said reinforcing bracket and transmitted through saidjointing means for further dispersion.
 5. The armrest mounting structureas defined in claim 1, wherein a securing bracket is provided at anupper frame section of said seat back frame, so that said upper securingpart of said reinforcing bracket is firmly secured to said securingbracket, and wherein a securing block is provided at said lower framesection of said seat back frame, so that said lower securing part ofsaid reinforcing bracket is firmly secured to said securing block. 6.The armrest mounting structure as defined in claim 5, wherein said uppersecuring part of said reinforcing bracket is formed with an engagementhole and said securing bracket is formed with an engagement lug to beengaged latchingly into said engagement hole.